JPS63280741A - Liquid crystal organopolysiloxane and production thereof - Google Patents

Abstract

PURPOSE:To provide a liquid crystal organopolysiloxane containing one or more F-containing alkyl groups and methogen groups in one molecule, exhibiting liquid crystal nature near the room temperature and suitable for the display and recording, etc., of optical information. CONSTITUTION:A liquid crystal organopolysiloxane having an average molecular weight of 500-100,000 and containing one or more R<1>R<2>SiO units and one or more R<3>R<4>SiO units (R<3> is methogen) in one molecule is produced by the addition reaction of a methogen compound containing alkenyl group to a straight-chain organopolysiloxane containing one ore more R<1>R<2>SiO units [R<1> is F-containing alkyl group (e.g. trifluoropropyl group); R<2> is lower alkyl (e.g. methyl)] and one or more R<4>HSiO units (R<4> is lower alkyl) in the presence of a platinum- based catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an organopolysilone N-sane that exhibits liquid crystallinity at a relatively low temperature, that is, around room temperature, and a method for producing the same.

[Prior Art and Problems, αJ Conventionally, many organic compounds that exhibit liquid crystal properties in a certain temperature range have been proposed.

Furthermore, many polymer compounds have been proposed that contain groups exhibiting liquid crystal properties in their main chains or side chains, and exhibit liquid crystal properties themselves. Among them, organopolysiloxanes exhibiting liquid crystal properties are disclosed in, for example, JP-A-56-79173, JP-A-57-165480, and JP-A-1111-1986.
It is shown in the publication No.-252486. Japanese Unexamined Patent Publication 1983-1979
No. 173 describes a linear organopolysiloxane having a mesogen group in the side chain, and JP-A No. 5
4 Same as No. 7-165480 fl (about cyclic organopolysilone
Publication No. tμ has a description of branched organopolysilone N-sane.

However, these conventional organopolysiloxanes generally exhibit liquid crystallinity at a relatively high temperature, and do not exhibit liquid crystallinity unless heated considerably.

[Objective of the Invention 1] In view of the above-mentioned drawbacks of the conventional liquid crystalline organopolysilone-N-sane, an object of the present invention is to provide an organopolysilone-N-sane that exhibits liquid crystallinity at relatively low temperatures, particularly around room temperature, and a method for producing the same. It's about doing.

[Structure of the Invention J The object of the present invention described above is to provide at least one R' R2S i O71 in one molecule.
position (It' is a fluorine atom-containing fulkyl group, R2 is a lower fulkyl group) and at least one R3R4S
A linear liquid crystalline organopolysiloxane having iO units (R3 is a mesogen group, R+ is a lower alkyl group).

and at least one R'R"SiO unit (R'
is an alkyl group containing 7 atoms, and R2 is a lower furkyl group. ) and at least one R'H61O unit (R
' is a lower alkyl group. ) with at least one R1R2SiO unit and at least one R1R2SiO unit in one molecule, characterized in that an alkenyl group-containing mesoden compound is subjected to an addition reaction to a linear organopolysilone N-sane having R3R4SiO unit ([(l,
R2 and R4 are the same as above, and R3 is a mesogen group. ) of linear liquid crystalline organopolysilone N-san! ! This can be achieved through the following methods:

To explain this in detail, the linear liquid crystalline organopolysilosane of the present invention has at least one R
1 R2SiO unit and at least one R2R'Si
In addition to the mandatory O unit, Rrs; o unit and R: 5
may contain iOo, s units, where Rs is a group selected from an alkyl group, a flukoxy group, an alkenyl group, a 71nol group, an aralkyl group, a hydrogen atom, a hydroxyl group, and optionally a mesogen group.

It is sufficient that one R1R2SiO unit, which is an essential unit constituting the organopolysiloxane of the present invention, is contained in one molecule, but in order to achieve good liquid crystallinity at low temperatures, it is necessary to contain all the siloxane units. Preferably, 10 mole percent or more of the units are this unit, where R' is an alkyl group containing 7 atoms, and the punch has the formula CnFzn++-(C
H2) is a group represented by -1, where n is usually a number from 1 to 20, and - is a number from 1 to 210. However, it is not necessarily necessary to follow this formula, and it is sufficient that the fulkyl group is substituted with at least one fluorine atom.From an economic point of view, This is a furkyl group, and examples thereof include those having 10 or less carbon atoms such as methyl, ethyl, propyl, and butyl groups, and methyl is the most preferred from an economical point of view.

I?, which is another essential unit for the organopolysilone N-sane of the present invention? 3R4SiO unit is 1 in 1 molecule.
It is sufficient if the unit is contained, but in order to develop good liquid crystallinity, it is preferable that this unit constitutes at least 30 mol% of the total siloxane I1 position.Here, R4 is a lower alkyl group as in R2 described above. From an economic point of view, it is also preferable to provide a methyl group.

The mesogen group represented by R1 is a conventionally known liquid crystallinity imparting group, and its structure is not particularly limited. In this group, a mesogen molecule is bonded to a silicon atom via a suitable linking group. , -(Ct
l2)p-1-C)-1(CHs)-(Ctl
2) A fullkylene group such as Q- or an alkylene/oxy group in which an oxygen atom is bonded to the alkylene group (p+q is a number from 1 to 220), exemplified as a mesoden molecule is benzoic acid phenyl ester , benzoic acid biphenyl ester, biphenyl, bennolyteaniline,
7zoxybenzene, azobenzene, ship base, cyclohexyl phenyl ether, cyclohexylbenzene,
Cyclohexylcarboxylic acid phenyl ester, cholesterin, furestane and their derivatives. Often + for mesogen monomers? As is known, special effects such as dielectric anisotropy can be imparted by bonding a polar group such as an alkoxy group or a nitrile group to the mesoden molecule.

Furthermore, two or more mesogenic groups may be present in the organovorin fuxa 21 molecule, which often helps to obtain good liquid crystal properties.

In the preferred straight nail-shaped liquid crystalline oligopolysiloxane of the present invention, R' is a dribble opipropyl group, and R3
is an organic group containing a 1n-substituted or unsubstituted biphenyl group, R2 and R'' are methyl groups, and the average molecular weight is 5.
00 to 100,000.

The method for producing liquid crystalline Olga/polysiloxane of the present invention includes:
An alkenyl group-containing method is added to an IF M (or)/polysiloxane containing at least one RI R'SiO unit and at least one R'11SiOlit position as essential components in one molecule in the presence of a platinum-based catalyst. It can be easily produced by subjecting the compound to one addition reaction.

In this method, the raw material straight (r)-shaped polysiloxane is composed of a low molecular weight cyclic or linear organopolysiloxane oligomer consisting of R'R'' SiO units and R'1
It can be obtained by equilibration polymerization of an ol/hydronoemborisilogysan oligomer consisting of -ISiO units in the presence of an acidic catalyst. Methods for producing alkenyl group-containing mesoden compounds are known, for example 1,
It is described in Publication No. 79173. As the catalyst used in the addition reaction, a platinum-based catalyst used in a so-called hydrosilylation reaction is effective, and chloroplatinic acid and its alcohol solution, an olefin complex of platinum, a complex of platinum and a vinyl group-containing siloxane, etc. are preferable. Examples include:

This addition reaction is preferably carried out in the presence of a suitable solvent, but can also be carried out without a solvent. Examples of solvents include aromatics such as benzene, toluene, and xylene, aliphatics such as hexane and heptane, ethers such as tetrahydro-7, noethyl ether, 7-tal, and ethyl ether. (Alcohols such as alcohol, flobor, butar, acetone, methyl ethyl ketone)
esters such as ethyl acetate, butyl acetate, chlorinated hydrocarbons such as carbon tetrachloride, trichloroethane, chloroform,
Although the reaction with dimethyl sulft oxide and the like can be carried out at room temperature, it is usually advantageous in terms of reaction rate to carry out the reaction at a temperature of about 50 to 200°C.

[Example] The following examples are shown to explain the present invention. In 0 examples, "part" means 1" part by weight. In addition, the liquid crystallinity is
The test was carried out by placing a sample between two orthogonal polarizing plates and observing the transmitted light with a microscope while changing the temperature. In the examples, the range showing liquid crystallinity is [solid and fluid 1]
It shows two points: ``the temperature that is the boundary between liquid crystal and isotropic liquid'' and ``the temperature that is the boundary between liquid crystal and isotropic liquid.''

Example 1 In a four-bottle flask, 15 g of octamethipane clotetrasiloxane, 48 parts of tetramethyl-tetrakis (triple oroprobyl) cyclotetrasiloxane, 244 parts of nato-2-methylcyclotetrasiloxane, 14 parts of tetramethylnosiloxane, and trimethylsiloxane as a catalyst were added. 0.1 part of 7-fluoromethanesulfonic acid was added, and the mixture was allowed to react at 100°C for 8 hours.
After cooling, it was neutralized with sodium hydrogen carbonate and filtered.
When unreacted substances were removed by vacuum distillation, a transparent polymer was obtained. del permeation chromatography (
GPC), infrared spectroscopy (IR), nuclear magnetic co-I-analysis (NMR), and 5itl titration analysis confirmed that this polymer has a structure represented by the following average formula.

This polymer is tentatively named FP-1.

65 parts of FP-1 in 4 flasks, 100 fi5 of l)+9'-aryloxysif/biphenyl,) 1 of toluene
000 g, a complex of platinum and tetramethyldivinyldisilosan with a platinum amount of F L) -1 of 200 ppp.
It was added so that the amount was m. After 10 hours and 7 hours, I sampled it and confirmed it by IR, and found that 5ill.
The peak had disappeared. The solvent was distilled off under reduced pressure to obtain a light gray paste-like polymer.
MR confirmed that p+9'-allyloxycyanobi7.enyl caused an addition reaction with SiH and was bonded to FP-1. The produced organopolysiloxane exhibited liquid crystallinity in the range from 25°C or lower to 65°C.

Example 2 In a fourth flask, a hydrolyzed angular condensate of methyl()'7fluoroprobyl)nomethoxysilane (average molecular weight 1950
) 1201TI'i, polymethylhydrodiene siloxane with trimethylsiloxy group capped at both ends (average molecular 41
2600) 50 parts, 2.8 parts of hexamethylnosiloxane and 0.0 parts of triple olomethanesulfonate as a catalyst.
18ffQ was added and reacted at 80°C for 6 hours. After cooling, the mixture was neutralized with accumulated sodium carbonate and filtered. When unreacted substances were removed by vacuum distillation, a transparent polymer was obtained. del permeation chromatography (G
P C), infrared spectroscopy (I n), nuclear magnetic resonance analysis (N M r? ), and SiH titration analysis confirmed that this polymer has a structure represented by the following average formula.

This polymer will be tentatively named FP-2.

Fourth, in a 7-glass tube, add 25 parts of FP-2, 26 parts of Ll+9'-allyloxycyanopyphenyl, 400 parts of toluene, and add an impropatul solution of chloroplatinic acid to a solution with a platinum content of FP-
It was added at a concentration of 100 ppm to 2. 15
After 97 lux, it was sampled and confirmed by IR, and it was found that the SiH peak had disappeared. The solvent was removed by distillation under reduced pressure to obtain a white candy-like polymer. Is this polymer NMI? As a result, 9+I)'-allyloxycyanobiphenyl undergoes an addition reaction with SiH, resulting in FP
It was confirmed that it was bound to -2. The produced organopolysiloxane exhibited liquid crystallinity in the range from 25°C or lower to 70°C.

Comparative example 1 For comparison, the following organopolysiloxane was synthesized.

CI+.

(2) This organopolysiloxane exhibited liquid crystallinity at 128 to 160°C.

Example 3 28 parts of FP-2, 42 parts of biphenyl p-allyloxyamino Q''I acid, 400 parts of toluene, and an in-propar solution of chloroplatinic acid were placed in a four-bottle flask with an amount of platinum relative to FP-2. It was added so that the concentration was 150 pp-.
After sampling, IRI confirmed that the SiH peak had disappeared. The solvent was removed by vacuum distillation to obtain a white powdery polymer.

It was confirmed by NMR that this polymer underwent an addition reaction with 5il of p-7 lyloxybenzoate biphenyl (2!) and was bonded to FP-2. It showed liquid crystallinity in the range up to .

Comparative example 2 For comparison, the following organopolysiloxane was synthesized.

(Cll=)zsiO(S+O)<. 5i(ell-)
iC mountain 0 units cooite ○ This organopolysiloxane exhibited liquid crystallinity at 145 to 182°C.

[Effect of the Invention 1] As is clear from the Examples and Comparative Examples, the linear liquid crystalline organopolysiloxane of the present invention contains at least one fluorine atom-containing alkyl group and at least one mesogen group in one molecule. Because of this, they exhibit liquid crystallinity in a lower temperature range compared to those that do not contain a fluorine atom-containing alkyl group, and many of them exhibit liquid crystallinity even at low temperatures around room temperature. In addition, the manufacturing method thereof can be easily produced by using a hydrosilylation reaction.The liquid crystalline organopolysiloxane of the present invention is useful for displaying and recording optical information by utilizing the above-mentioned properties. .

Claims (1)

[Claims] 1. At least one R^1R^2SiO unit (R^1 is a fluorine atom-containing alkyl group, R^2 is a lower alkyl group) and at least one R^2 in one molecule. 3R
A linear liquid crystalline organopolysiloxane having ^4SiO units (R^3 is a mesogen group, R^4 is a lower alkyl group). 2. The liquid crystalline organopolysiloxane according to claim 1, wherein R^1 is a trifluoropropyl group and R^2 is a methyl group. 3. The liquid crystalline organopolysiloxane according to claim 1, wherein R^3 is an organic group containing a substituted or unsubstituted biphenyl group, and R^4 is a methyl group. 4 The average molecular weight of liquid crystalline organopolysiloxane is 50
The liquid crystalline organopolysiloxane according to claim 1, which has a molecular weight of 0 to 100,000. 5 At least one R^1R^2SiO unit in one molecule (R^1 is a fluorine atom-containing alkyl group, R^2 is a lower alkyl group) and at least one R^4H
In one molecule, a linear organopolysiloxane having SiO units (R^4 is a lower alkyl group) is subjected to an addition reaction with an alkenyl group-containing mesogen compound in the presence of a platinum catalyst. at least one R in
^1R^2SiO unit and at least one R^3R
A method for producing a linear liquid crystalline organopolysiloxane having ^4SiO units (R^1, R^2 and R^4 are the same as above. R^3 is a mesogen group). 6. The method for producing a liquid crystalline organopolysiloxane according to claim 5, wherein R^1 is a trifluoropropyl group and R^2 is a methyl group. 7. The method for producing a liquid crystalline organopolysiloxane according to claim 5, wherein R^3 is an organic group containing a substituted or unsubstituted biphenyl group, and R^4 is a methyl group. 8 The average molecular weight of liquid crystalline organopolysiloxane is 50
0 to 100,000, the method for producing a liquid crystalline organopolysiloxane according to claim 5.